Recently, portable terminal devices such as feature phones and smart phones have various functions in addition to a telephone function. One of such functions is a camera function. The portable terminal device may capture a high resolution image by a sophisticated camera function.
For example, the portable terminal device includes a camera lens, image capturing element, a red green blue (RGB) sensor, and so forth and may perform image correction such as white balance adjustment to an image captured by the camera lens and the image capturing element by using the RGB sensor. This allows the portable terminal device to capture a natural image regardless of an outdoor or indoor image capturing position. The RGB sensor that is used for such image correction is provided on a side on which the camera lens is installed, for example.
Differently, there is a case where the portable terminal device includes a display screen such as an LCD and the RGB sensor is installed on a side on which the display screen is provided. The RGB sensor provided on the display screen side is used for adjustment of colors on an image displayed on the display screen and as a proximity sensor, for example. In a case where the RGB sensor is used as the proximity sensor, when a face approaches a microphone or a speaker provided in the portable terminal device on a call, the RGB sensor provided on the display screen side detects the face, and a power supply to the display screen is temporarily turned off. Reduction in power consumption of the portable terminal device may thereby be expected, for example.
As for such image correction, the following technologies are disclosed, for example. For example, Japanese Laid-open Patent Publication No. 2011-203437 discloses a technology in which a first photometric sensor is provided on a display side of a display section in an electronic camera, a second photometric sensor is provided on a back side of the display side of the display section, and the display section thereby displays a corrected image to which adjustment is applied in accordance with a lighting environment by using a first lighting condition from the first photometric sensor and a second lighting condition from the second photometric sensor.
It is considered that this technology may provide a unit that properly adjusts appearances of colors of the image displayed on the display section in accordance with brightness of an environment.
Further, Japanese Laid-open Patent Publication No. 2003-102018 discloses a technology in which in an electronic still camera that includes a white balance adjustment unit that performs white balance adjustment based on a captured image, reliability of a stored white control signal is assessed based on the number of image capturing frames and an elapsed time from a prescribed time point, and a user is notified of low reliability in a case where the reliability is low.
It is considered that this technology may minimize incorrect white balance adjustment that occurs at an actual image capturing time point in a case the light source conditions of the lighting are different.
Further, Japanese Laid-open Patent Publication No. 2008-219128 discloses an image capturing device that changes image capturing modes by controlling the white balance of an image signal obtained by a charge coupled device (CCD) in accordance with the difference between an average first color of an atmosphere that is measured by a color sensor and an average second color of an object that is measured with the image signal.
It is considered that this technology may provide an image capturing device that may perform adjustment to an appropriate white balance in a short time.